Despite the large number thereof, anticancer agents developed thus far can cure only a few cancers completely. The reason why most cancers cannot be cured completely is that cancer is resistant to anticancer agents, or that tumors are reduced in size in the early stages of chemotherapy, but becomes resistant to anticancer agents during or after chemotherapy. In order to effectively treat cancer with anticancer agents, therefore, chemo-resistance, that is, the resistance of cancer cells to chemicals, must be overcome.
Glucosamine is a major component of chitin, a structural polysaccharide found in large quantities in the exoskeletons of crustaceans, such as shells of marine crabs and shrimps, and safe for the body. Thus, the use of glucosamine in cosmetic compositions (Korean Pat. Application No. 10-2005-7014642) and for the development of arthritis therapeutics (Korean Pat. Application Nos. 10-2005-009182 and 10-2004-0057849) has been attempted. However, it is disclosed in the present invention for the first time that when anticancer agents are administered together with glucosamine, cancer cells are increased in sensitivity to anticancer agents, and thus glucosamine can be used as a cancer sensitizer.
Leading to the present invention, intensive and thorough research into effective chemotherapy, conducted by the present inventors, resulted in the finding that glucosamine or derivatives thereof can reduce the chemo-resistance of cancer cells.